Mistreatment of dementia patients by spousal care providers is fairly common. Caregivers’ characteristics, particularly their psychosocial, physical and cognitive functioning, and coping behaviours, predict reports of elder mistreatment. Parental caregivers of children with autism spectrum disorder (ASD) however, despite the similarities they share with dementia caregivers, have not been studied in this context. A sample of N = 95 caregivers of children with ASD completed an online survey assessing: (a) psychosocial, physical and cognitive functioning, and (b) coping behaviours. Caregivers also: (c) rated the extent to which they used potentially harmful psychological (e.g., screamed at the child) and physical (e.g., slapped the child) behaviours to cope with caregiving challenges over the last 12 months. Rates of potentially harmful psychological and physical behaviours were extremely low. However, 95% of caregivers reported using at least one potentially harmful psychological behaviour at some point in the last 12 months, and almost 38% reported using at least one potentially harmful physical behaviour. Mediation analysis yielded an indirect effect of psychological distress on potentially harmful psychological behaviours through disengaged coping. In conclusion, rates of potentially harmful behaviours appear to be low in the context of caring for a child with ASD. Caregivers reporting increased psychological distress were more likely to use potentially harmful psychological behaviours, and this effect was partially mediated by greater use of disengaged coping.